Open Inbox, No New Mail Inbox
This is an empty inbox. Its door is open, and the inside is empty. The flag that is put away also means that there are no new letters to receive.
The design color of most platforms is blue, and the design of a small number of platforms is gray.
This emoticon can express the same meaning as "No letter to be received ", it can mean that there is no new letter, or it can mean postal delivery.
